Drug Interaction Risk in Cancer Care

April 17, 2007 -- Potential drug interactions may be common in cancer
patients, especially those taking drugs for multiple conditions.

That news appears in the Journal of the National Cancer
Institute.

Many cancer patients have multiple health problems and see various doctors.
Coordinated care and computerized prescription screening might help prevent
drug interactions, states an editorial published with the study.

The researchers who worked on the study included Monika Krzyzanowska, MD,
MPH, of Princess Margaret Hospital in Toronto.

The editorialists included Peter Norton, MD, CCFP, FCFP, of the family
medicine department at Canada's University of Calgary.

Drug Interaction Study

Krzyzanowska and colleagues gave surveys to 405 cancer patients treated at
Princess Margaret Hospital, Canada's largest cancer center, between September
2005 and May 2006.

In the surveys, the patients reported all the drugs they had taken in the
previous month, including cancer drugs and drugs for other conditions.

On average, the cancer patients were 58 years old, were taking five drugs,
and also had one noncancerous condition.

Their most common noncancerous conditions were heart disease,
musculoskeletal disorders, underactive thyroid (hypothyroidism), or
depression.

The researchers used a computer program to analyze all potential drug
interactions in the patients' drugs.

They found 276 potential drug interactions in 109 patients. Those figures
are based on the computer analysis, not on problems reported by the
patients.

Nearly 90% of the potential drug interactions involved drugs unrelated to
cancer treatment, which included the blood-thinning drug warfarin, drugs that
treat high blood pressure, aspirin, and antiseizure drugs.

Most of the potential drug interactions -- 77% -- were moderately severe,
according to the computer program.

The researchers and editorialists call for more studies to develop
strategies to prevent potential drug interactions.